1. Field of the Invention
The present invention relates to a home network in which home electric appliances, computers, and peripheral devices are connected through a network. The present invention also relates to a content playback apparatus, a server connection method, and a recording medium, which are used for connecting with a server on the network.
2. Description of the Related Art
In recent years, network techniques for connecting home electric appliances, computers, and peripheral devices through a network, transmitting/receiving the state of each device and various information, so as to improve the convenience and comfort for users, have been proposed. An in-home network, particularly, a network for connecting home electric appliances and computers, is referred to as a home network.
As the above-described home network, a network technique using a universal plug and play (UPnP) has been proposed. In UPnP, a user only has to connect home electric appliances, computers, and peripheral devices through a network, without complicated operations and setup operations. In order to allow the home network to operate, devices connected through the network need to automatically obtain information about the other devices so that each device on the network can transmit/receive information to/from the other devices on the network.
Accordingly, in a home network using UPnP, when an apparatus (client terminal) is brought into connection with the network, the client terminal can automatically find a server providing various services. More specifically, as shown in FIG. 15A, when a client terminal 1 is connected to a home network 3 (the connection includes power-on and start-up of application), the client terminal 1 issues a service discovery request (SD request), which is transmitted through the home network 3. In response to this request, as shown in FIG. 15B, servers 2-1 to 2-4 on the home network 3 transmit responses including their addresses and server names (host names) on the network and service content to the client terminal 1. The client terminal 1 receives the responses from the servers 2-1 to 2-4 so as to obtain information including the server names and addresses of the servers 2-1 to 2-4, the information being used forFF connection.
In the above-described home network using UPnP, a user has to wait for responses from all the servers 2-1 to 2-4 on the home network 3, the time depending on the number of servers. For example, the user waits for the response from each server for about 10 seconds, and the user obtains the list of servers when a timeout occurs. Therefore, the user has to wait for about 10 seconds of search processing in order to obtain the list of servers.
In order to solve this problem, the list of serves on the home network 3 may be registered on the client terminal 1 in advance. However, all the servers 2-1 to 2-4 on the home network 3 do not always operate, and the client terminal 1 is not always connected to the home network 3. Thus, the list of servers registered in advance cannot be used in practice. Also, one of the characteristics of UPnP, that is, flexible participation to a network, plug and play, will be damaged. Therefore, the list of serves 2-1 to 2-4 on the network 3 must be obtained every time the client terminal 1 is connected to the home network 3 or every time an application is started up, and thus a waiting time for search processing is inevitably generated.
Further, the user must select a server to be connected from the list of servers every time he or she connects the client terminal 1 to the network 3 or every time he or she starts up the application. If the number of servers on the home network 3 is small, a problem does not occur. However, if the number of servers is large, a complicated operation is needed for selecting a server, and the degree of convenience is decreased.